title: Circular dichroism and superdiffusive transport at the surface of BiTeI.
abstract: We investigate the electronic states of BiTeI after the optical pumping with circularly polarized photons. Our data show that photoexcited electrons reach an internal thermalization within 300 fs of the arrival of the pump pulse. Instead, the dichroic contrast generated by the circularly polarized light relaxes on a time scale shorter than 80 fs. This result implies that orbital and spin polarization created by the circular pump pulse rapidly decays via manybody interaction. The persistent dichroism at longer delay times is due to the helicity dependence of superdiffussive transport. We ascribe it to the lack of inversion symmetry in an electronic system far from equilibrium conditions.
authors.affiliation: Laboratoire de Physique des Solides, CNRS-UMR 8502, Université Paris-Sud, FR-91405 Orsay, France.
authors.forename: J
authors.initials: J
authors.lastname: Mauchain
authors.forename: Y
authors.initials: Y
authors.lastname: Ohtsubo
authors.forename: M
authors.initials: M
authors.lastname: Hajlaoui
authors.forename: E
authors.initials: E
authors.lastname: Papalazarou
authors.forename: M
authors.initials: M
authors.lastname: Marsi
authors.forename: A
authors.initials: A
authors.lastname: Taleb-Ibrahimi
authors.forename: J
authors.initials: J
authors.lastname: Faure
authors.forename: K A
authors.initials: KA
authors.lastname: Kokh
authors.forename: O E
authors.initials: OE
authors.lastname: Tereshchenko
authors.forename: S V
authors.initials: SV
authors.lastname: Eremeev
authors.forename: E V
authors.initials: EV
authors.lastname: Chulkov
authors.forename: L
authors.initials: L
authors.lastname: Perfetti